DreamBig.SourceGen.Dapper.SqlServer 1.0.0-beta.10

DreamBig.SourceGen.Dapper

DreamBig.SourceGen.Dapper provides compile-time SQL generation for Dapper users who want to avoid raw SQL in application code.

Features

• Attribute-driven repository generation ([DbRepository])
• Entity mapping attributes ([DbTable], [DbColumn], [DbKey], [DbIgnore])
• Generated CRUD methods
• Generated stored procedure execution with output parameter support
• Generated INNER/OUTER joins from method-level attributes
• Provider-specific SQL generation (SQL Server and PostgreSQL)

Target Frameworks

Runtime library supports:

• net10.0

Install

• SQL Server: DreamBig.SourceGen.Dapper
• PostgreSQL: DreamBig.SourceGen.Dapper.PostgreSql

DI Setup

SQL Server:

using DreamBig.SourceGen.Dapper.SqlServer;

services.AddDreamBigDapperSqlServer(configuration);
services.AddDreamBigDapperGenerated();

PostgreSQL:

using DreamBig.SourceGen.Dapper.PostgreSql;

services.AddDreamBigDapperPostgreSql(configuration);
services.AddDreamBigDapperGenerated();

Configuration sections:

• SQL Server: DreamBig:Dapper:SqlServer
• PostgreSQL: DreamBig:Dapper:PostgreSql

Overloads are available for raw connection strings and custom connection string factories.

Quick Start

using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using DreamBig.SourceGen.Dapper.Attributes;

[DbTable("Customers", Schema = "dbo")]
public sealed class Customer
{
    [DbKey]
    public int Id { get; set; }

    [DbColumn("full_name")]
    public string Name { get; set; } = string.Empty;

    public string Email { get; set; } = string.Empty;
}

[DbRepository]
public interface ICustomerRepository
{
    Task<int> InsertCustomer(Customer entity, CancellationToken cancellationToken);
    Task<int> UpdateCustomer(Customer entity, CancellationToken cancellationToken);
    Task<int> DeleteCustomer(int id, CancellationToken cancellationToken);
    Task<Customer?> GetByIdCustomer(int id, CancellationToken cancellationToken);
    Task<IEnumerable<Customer>> GetAllCustomers(CancellationToken cancellationToken);
}

The source generator emits CustomerRepositoryGenerated, with SQL and Dapper calls already implemented.

Primary Key Without [DbKey]

You can define the primary key directly on DbTableAttribute using PrimaryKey. This is useful when the entity class comes from another team/package and you do not want to modify the entity source.

using System.Threading;
using System.Threading.Tasks;
using DreamBig.SourceGen.Dapper.Attributes;

[DbTable("Customers", Schema = "dbo", PrimaryKey = "CustomerId")]
public sealed class ExternalCustomer
{
    public int CustomerId { get; set; }
    public string Name { get; set; } = string.Empty;
}

[DbRepository]
public interface IExternalCustomerRepository
{
    Task<int> UpdateCustomer(ExternalCustomer entity, CancellationToken cancellationToken);
    Task<int> DeleteCustomer(int customerId, CancellationToken cancellationToken);
    Task<ExternalCustomer?> GetByIdCustomer(int customerId, CancellationToken cancellationToken);
}

PrimaryKey can match either:

• the CLR property name (CustomerId), or
• the mapped SQL column name when DbColumnAttribute is used.

Join Example

using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using DreamBig.SourceGen.Dapper.Attributes;

[DbQuery(From = "Customers", Schema = "dbo", Where = "[IsActive] = @isActive", OrderBy = "Id", OrderByDirection = OrderByDirection.Desc)]
[DbJoin(JoinType = JoinType.Left, JoinTable = typeof(Order), JoinColumnA = "Id", JoinColumnB = "CustomerId", Schema = "sales")]
Task<IEnumerable<CustomerSummary>> QueryActive(bool isActive, CancellationToken cancellationToken);

Notes:

• The generator assigns table aliases (t0, t1, ...) automatically.
• OrderBy expects a column/property name only; use OrderByDirection to control sort direction.
• JoinColumnA and JoinColumnB must match CLR property names on the base entity and join entity (validated at compile time).

Stored Procedure Example

using System.Data;
using System.Threading;
using System.Threading.Tasks;
using DreamBig.SourceGen.Dapper.Attributes;
using DreamBig.SourceGen.Dapper.Internal;

[DbStoredProcedure("usp_customer_summary", Schema = "dbo")]
Task<GeneratedProcedureResult<CustomerSummary>> GetSummary(
    [DbParam("@customerId", DbType = DbType.Int32)] int customerId,
    [DbParam("@total", Direction = DbParamDirection.Output)] int total,
    CancellationToken cancellationToken);

Unit Of Work Example

using System;
using System.Threading;
using System.Threading.Tasks;
using DreamBig.SourceGen.Dapper.Attributes;

[DbUnitOfWork]
public interface IAppUnitOfWork
{
    ICustomerRepository Customers { get; }
    IOrderRepository Orders { get; }
}

// generated type: AppUnitOfWorkGenerated
var uow = new AppUnitOfWorkGenerated(() => new SqlConnection(connectionString));

await uow.BeginTransactionAsync(cancellationToken: cancellationToken);
try
{
    await uow.Customers.UpdateCustomer(customer, cancellationToken);
    await uow.Orders.DeleteOrder(orderId, cancellationToken);
    await uow.CommitAsync(cancellationToken);
}
catch
{
    await uow.RollbackAsync(cancellationToken);
    throw;
}

Notes:

• Insert*, Update*, Delete*, and stored procedure methods require an active transaction and throw InvalidOperationException otherwise.
• Read/query methods can execute with or without an active transaction.

Known Limitations (v1)

• SQL dialect support is limited to SQL Server and PostgreSQL.
• Stored procedures support one mapped result set plus output parameter capture.
• Complex projection/multi-mapping scenarios are not yet generated.

Dialect Packages

The generator emits SQL based on the provider-specific package you install (DreamBig.SourceGen.Dapper for SQL Server, DreamBig.SourceGen.Dapper.PostgreSql for PostgreSQL) while preserving the same attribute contracts.